#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>

#define FNAME "/tmp/out"
#define BUFSIZE 1024

int main()
{
    FILE *fp;
    char buf[BUFSIZE];
    time_t stamp;
    struct tm *tm;
    int count = 0;
    
    
    fp = fopen(FNAME, "a+");
    if(fp == NULL)
    {
        perror("fopen()");
        exit(1);
    }

    while(fgets(buf, BUFSIZE, fp) != NULL)
        count++;

    while(1)
    {
        time(&stamp);
        tm = localtime(&stamp);
        fprintf(fp, "%-4d%d-%d-%d %d:%d:%d\n ", ++count, \
                tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,\
                tm->tm_hour, tm->tm_min, tm->tm_sec);
        fflush(fp);
        sleep(1);
    }

    fclose(fp);

    exit(0);
}
